I believe I study one. It could be argued that I study three (boxing, Greco-Roman and Brazilian jiu-jitsu).

As I don't study them separate from each other, I honestly I believe I just study one - the art of human physical combat. So is that one art or many arts? I suppose the depends on how you define things.

Interesting poll. While I have formally studied 3 arts over the years, I have only ever done 1 at a time. That said, I have poked around informally in other arts, while training formally in something else at the same time.

_________________________"In case you ever wondered what it's like to be knocked out, it's like waking up from a nightmare only to discover it wasn't a dream." -Forrest Griffin